Ankle-joint for artificial limbs.



' P a t e n t e d F e b 5 I 9 0 l.

ANKLE JOINT F IIIIIIIIIIIIIIIIII S.

UNTTnn STaTns IRVIN R. FENNER AND WILLIAM D. FENNER, OF SAN FRANCISCO, CALI- FORNIA.

ANKLEAJOINT FOR ARTIFIGIAL LIMBS.;

SPECIFICATION forming part of Letters Patent N o. 667,511, dated February 5, 1901.

Application filed October 22, 1900. Serial No. 335985. (No model.)

T a/ZZ wwn t nza/g concern:

Beit known that we, IRVIN R. FENNER and WILLIAM D. FENNER, citizens of the United States,residing at San Francisco,in the county of San Francisco and State of California, have invented certain new and useful Improvements in Ankle-Joints for Artificial Limbs, of which the following is a specification.-

Our invention relates to improvements in ankle-joints for artificial limbs, one object of our invention being to provide a joint which shall permit movement of the foot with very little friction and which shall at the same time be very strong and equalize the strain on both sides of the foot, so as to cause the foot to rest always squarely upon the floor, and one, moreover, in which the extent of movement of the joint shall not be unduly limited, but which permits the foot to bend as far as needed.

A further object of ourinvention is to provide a device of this character which can be attached and removed with very little trouble.

Our in vention therefore resides in the novel construction, combination, and arrangement of parts for the above ends hereinafter fully specified, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a longitudinal vertical section of an artificial` shin and foot attached by means of our improved ankle-joint. Fig. 2 is a transverse section of the same; and Fig. 3 is a longitudinal section taken on the line A A of Fig. 2, showing the ankle-joint detached.

Referring to the drawings, 1 represents the shin portion of an artificial limb, and 2 the foot portion thereof. Upon a specially-prepared groove 3, sunk into the upper portion of the foot, rests a semicylindrical plate or lower member 4, said plate having a groove 5 near each end to receive balls 6, said balls being stopped at the end of said grooves by means of pins 7 in the plate 4. Upon these two series of balls rolls the upper member 8 of the joint, having a general cylindrical form and having at its ends the annular grooves 9 to receive said series of balls 6. Said upper member or cylinder 8 is secured to the shin portion of the leg by means of rods 10, which are passed through said upper member and also through the solid portion 11 of the' shin and are anchored thereto by means of nuts 12, said nuts permitting thejoint to be readily secured to limbs of dierent sizes.

The lower member or plate 4 of the joint is secured to the foot 2 by means of a rod 13, which passes through an aperture 14 in said lower memberk and also through an elongated or slotted aperture 15 in the cylinder 8 and is secured to a cylindrical head 16, rotating in said upper member. The pin 17, driven through the rod 13, secures the platetthereto. The rod 13 passes through the foot and is anchored thereto by means of a nut 18. Itwill be seen that with this construction all that is necessary in order to remove the foot from the shin portion is to unscrew the nut 18 and withdraw the foot from the rod 13 and the ankle-joint. The ankle-joint may similarly be removed from the shin portion by unscrewing the nuts 12. When the joint is removed, the several parts thereof will still be connected, and there is no possibility of the balls falling out or being lost when the limb is taken apart. At the same time the joint is a very strong one, owing to the fact that the upper member has a double bearing on the lower mem ber viz.,the ball-bearing-and the cylindrical head 16 rotating within the cylindrical socket of the upper member. The ball-bearings at the extreme ends of the joint tend to equalize the strain on both sides of the foot. The greatest pressure is evidently' taken up by the ball-bearings, said bearings sustaining the direct weight of the leg and body upon the foot. l

19 indicates rods which serve the purpose of returning the foot to its normal or horizontal position; but these rods form no part of our present invention.

Ve claim- 1. In an ankle-joint for an artificial limb, the combination of the upper member, secured to the shin portion, the lower member, said upper and lower members being correspondingly grooved to containballs, the balls therein, and the rod for connecting the lower member to the foot, said rod having a cylindrical head rotating within the upper member, substantially as described.

2. In an ankle-joint for an artificial limb,

IOO

the combination with the shin portion and the foot portion of the limb, of upper and lower members having corresponding grooves at their ends, balls in said grooves, end stops for said balls, rods passed through the upper member, nuts for securing said rods tothe shin portion, a rod passed through the lower member, a nut for attaching said rod to the foot portion, and a cylindrical head rotating 1o within the upper member, to which head said latter rod is attached, substantially as described.

In witness whereof we have hereunto set our hands in the presence of two subscribing witnesses.

I. R. FENNER. WV. D. FENNER.

Witnesses:

FRANCIS M. WRIGHT, Z. A.. DANIELS. 

